Within a given population of interfaces, planar polarized interface behaviors occur on a continuum with interface angle. (A) Schematic of a typical t1 transition, with Myosin II localized to vertical (DV-oriented) interfaces and Bazooka/Par3 localized to horizontal (AP-oriented) interfaces. (A′) Schematic of embryo coordinate system, with AP/DV axis and interface angles indicated. (B) Heat map of the rate of change in interface length (red: contraction; blue: elongation) as a function of time t and interface orientation angle θ. Data is averaged from n = 2,940 unique interfaces from k = 3 embryos; time point t = 0 corresponds to the onset of germband extension, and orientation angle θ = 0° corresponds to vertical interfaces. (B′) Sample image of cells, with interfaces color-coded for their measured contraction/elongation rate; scale bar 5 µm. (C) Distribution of measured interface contraction/elongation rates for different interface orientation angle bins. Same data set as B, constrained to the time window t = 5–20 min after initiation of germband extension. (C′) Same data as C is shown as a box plot. (D) Mean interface contraction/elongation rates as a function of developmental time t, for different interface orientation angle bins (same data set as B). Full distribution of the data values in the grey-shaded areas is shown in Fig. S1, B and B′. (E) Mean interface contraction/elongation behavior during area oscillation cycles (oscillation phase angle ϕ), for different interface orientation angle bins (n = 1,736 unique interfaces in k = 4 embryos). Full distribution of the data values in the grey-shaded area is shown in Fig. S1, C and C′.